add_compile_options

Add options to the compilation of source files.

add_compile_options(<option> ...)

Adds options to the COMPILE_OPTIONS directory property. These options are used when compiling targets from the current directory and below.

Note

These options are not used when linking. See the add_link_options() command for that.

Arguments

Arguments to add_compile_options may use generator expressions with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

Option De-duplication

The final set of options used for a target is constructed by accumulating options from the current target and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.

Added in version 3.12: While beneficial for individual options, the de-duplication step can break up option groups. For example, -option A -option B becomes -option A B. One may specify a group of options using shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A" "SHELL:-option B" becomes -option A -option B.

Example

Since different compilers support different options, a typical use of this command is in a compiler-specific conditional clause:

if (MSVC)
    # warning level 4
    add_compile_options(/W4)
else()
    # additional warnings
    add_compile_options(-Wall -Wextra -Wpedantic)
endif()

To set per-language options, use the $<COMPILE_LANGUAGE> or $<COMPILE_LANGUAGE:languages> generator expressions.

See Also

• This command can be used to add any options. However, for adding preprocessor definitions and include directories it is recommended to use the more specific commands add_compile_definitions() and include_directories().

• The command target_compile_options() adds target-specific options.

• This command adds compile options for all languages. Use the COMPILE_LANGUAGE generator expression to specify per-language compile options.

• The source file property COMPILE_OPTIONS adds options to one source file.

• add_link_options() adds options for linking.

• CMAKE_<LANG>_FLAGS and CMAKE_<LANG>_FLAGS_<CONFIG> add language-wide flags passed to all invocations of the compiler. This includes invocations that drive compiling and those that drive linking.